a comparative study between resilon and gutta-percha as a secondary root canal filling materials: an in vitro study

introduction: adequate root canal seal following retreatment is essential for a successful outcome. resilon/epiphany (r/e) obturation system has been introduced as a substitute for conventional gutta-percha/sealer method. this in vitro study compared the amount of apical microleakage of r/e with gutta-percha/ah26 (gp/ah26) sealer as secondary root canal filling following retreatment in human teeth. materials and methods: fifty human single-rooted lower premolar teeth were selected. after preparing them with protaper rotary niti instruments, all the canals were obturated using gp/ah26 sealer. after 10 days, all the samples were retreated using the same rotary niti instruments. the samples were divided randomly into two experimental groups a and b (n=20) and positive and negative control groups (n=5). in group a, all canals were obturated using gp/ah26 sealer and in group b all canals were obturated using r/e. after one week incubation in 37˚c with 100% humidity, the amount of apical microleakage was evaluated with fluid filtration model. all the apical microleakage data were analyzed with mann-whitney u test.   results: the mean amounts of apical microleakage were 0.317 ± 0.287 and 0.307 ± 0.281 µl/8min (fluid pressure=30 cm h 2 o) in experimental group a and b respectively; the difference was not statistically significant (p>0.05). conclusion: r/e seems to be a good alternative for retreatment as a secondary root canal filling material. however, resilon/epiphany obturation system does not completely avert microleakage.